Turan, Ahmet İhsan; Çelik, Alper

This study presents a damage-based comparative assessment of reinforced concrete buildings affected by the 1992 Erzincan earthquake (Mw 6.8) and the 2023 Kahramanmaraş earthquake sequence (Pazarcık, Mw 7.7; Elbistan, Mw 7.6), two destructive earthquake events in Türkiye separated by nearly three decades. A distinctive contribution of the study is the presentation of original color photographs from the 1992 Erzincan earthquake, systematically documented and comparatively evaluated for the first time and directly compared with post-earthquake field observations from Malatya following the 2023 earthquake sequence. To complement the field-based evidence, representative strong ground motion records from both earthquake events were processed and compared using standard seismic intensity and spectral response parameters. The spectral evaluation indicates that the 1992 Erzincan ground motion and the 2023 Elbistan-related motion recorded in Malatya imposed comparable seismic demands relevant to typical reinforced concrete buildings, thereby providing a rational basis for cross-event damage interpretation. Despite substantial advances in Turkish seismic design codes, recurrent damage mechanisms were observed in both building stocks, particularly soft-story formation, short-column effects, inadequate transverse reinforcement, poor beam–column joint performance, and deficiencies in material quality and detailing. The findings demonstrate that seismic safety cannot be improved through code development alone unless design provisions are consistently translated into construction quality, detailing practice, inspection, and field implementation.

Oz, Mehmet Furkan; Kumbasaroglu, Atila; Yalciner, Hakan; Korozlu, Nurettin; Babacan, Yunus; Çatır, Fulya Esra Cimilli; Sayarcan, Done

Seismic metamaterial-inspired periodic foundations have emerged as promising vibration-mitigation concepts capable of attenuating seismic wave propagation within specific frequency bands. This study presents an experimental investigation on the dynamic response of periodic foundation configurations, with and without embedded piezoelectric layers, to evaluate their vibration-attenuation characteristics. The experimental program employed a shake table driven by a 0.75 kW servo motor and included excitation step counts of 3000, 4000, and 5000. Accelerometers mounted on the specimen surfaces recorded vibration data at 80 ms intervals. Three foundation configurations were tested: (i) a conventional reinforced concrete block, (ii) a one-dimensional periodic foundation composed of alternating concrete and rubber layers, and (iii) a periodic foundation incorporating piezoelectric modules. Time-domain and frequency-domain analyses showed that the periodic foundations achieved notable reductions in both peak and RMS accelerations, especially near resonance frequencies. The configuration, including piezoelectric layers, exhibited similar attenuation performance while also generating measurable instantaneous voltage outputs under vibration. However, these voltage peaks—reaching a maximum of 1.64 V—represent only a laboratory-scale, proof-of-concept demonstration of electromechanical coupling rather than a practical or continuous form of energy harvesting, given the inherently sporadic nature of seismic excitation. Overall, the results confirm that the tested system is not a full metamaterial in the classical sense but rather a metamaterial-inspired periodic arrangement capable of inducing band-gap-based vibration attenuation. The inclusion of piezoelectric elements provides auxiliary sensing and micro-energy-generation capabilities, offering a preliminary foundation for future multifunctional seismic-protection concepts.

Ulusu, İsmet

The main causes of damage include poor site selection, such as building on fault lines or on fill soil, as well as deficiencies in design, materials, and workmanship. Damage levels are also linked to the economic conditions of the region. In the 1939 earthquake, there were high casualties due to the magnitude of the earthquake, lack of engineering design in traditional structures and unsuitable soil conditions. Similarly, in the 1992 earthquake, unexpected damage occurred due to faulty designs created by inexperienced engineers who lacked sufficient knowledge of the seismic behavior of structures, errors in craftsmanship and workmanship, and unsuitable residential area selection for construction. These problems continue today and put most of the building stock at risk in case of a major earthquake. Seismic steel isolators are used in two new buildings in the city; if they are effective, they should be made mandatory in new construction. Otherwise, consideration should be given to relocating the city to the more stable southern rocky areas, which were unaffected in both 1939 and 1992.

Bulut, H. Alperen; Şahin, Remzi

A comprehensive evaluation of the results obtained according to the measurement of radon gas in buildings and concrete, which is the most consumed material in the world after water, in accessible studies carried out in the last 40 years is the main objective of this study. The paper additionally aims to address the gap in the literature by comparatively determining which parameters affect radon–concrete and radon–building relationships. The scientific knowledge compiled within the scope of this article was presented under the main headings of radon and radon gas measurements in concrete and buildings. Radon gas, also known as the “invisible killer”, is considered the second most important cause of lung cancer after smoking (the gas is responsible for 3–14% of lung cancer cases in the world). The results determined that radon concentration limits have been applied in the range of 100–400 Bqm−3 in houses and 100–3700 Bqm−3 in workplaces. Studies conducted on the exhalation rate of radon showed that the radon exhalation rate of concrete may be in the range of 0.23–510 Bqm−2 h−1. The results of indoor radon concentration measurements revealed that values between 4.6 Bqm−3 and 583 Bqm−3 were obtained. Despite the existing literature, some researchers state that there is an urgent need for an improved and widely accepted protocol based on reliable measurement techniques to standardize measurements of the radon exhalation rate of construction materials and the indoor radon concentration of buildings.

Ulusu, İsmet; Kurnuç Seyhan, Aslıhan

Polyurethane-based materials, which are widely used in exterior cladding, pose a great risk for buildings because they can easily catch fire at temperatures as low as 50–65 °C. Thus, different materials are needed to ensure that structures exposed to high temperatures do not have any stability problems. In this study, expanded perlite aggregate plaster (EPAP) was produced to eliminate the negative effects that may occur in buildings exposed to high temperatures. High temperature tests were carried out on test plates of different thicknesses to determine the effect of plaster thickness under high temperatures. In order to compare the effects of high temperatures, a test sample of normal aggregate plaster (NAP), which is widely used in buildings, was prepared. In the high temperature test, the temperature values on the back surfaces of the EPAP (≈115 °C) test plates were approximately 3 times lower than the temperature values of the NAP (≈350 °C) test plate. It can be said that structural stability loss and durability problems may occur in structures covered with NAP in a high-temperature environment, and that no negative effect will occur in terms of structural stability and durability problems in structures covered with EPAP in high temperature environments.

Dogan, Ahmet; Kayaci, Nurullah; Kanbur, Baris Burak; Demir, Hakan

Mean radiant temperature (MRT) is one of the six primary factors that determine thermal comfort in a given thermal environment. In this study, the average radiant temperature was determined using a calculation method based on the surrounding surface temperatures and view factors. The present study specifically investigated the use of calculated radiant temperature, compared to measured radiant temperature, for predicting the mean vote (PMV) and percentage of dissatisfied (PPD) comfort parameters. The method was validated by the experimental measurements via the black sphere thermometer at five different reference points in a test room, including radiant panels on the ceiling and walls. By using global thermometer measurements, the proposed approach achieved a high degree of compatibility and an accuracy of 0.17 °C, which was the difference between calculated and measured values. The results demonstrated the reliability of the procedure using view factors and surrounding surface temperatures to calculate the radiant temperature in the designated test room; here, a straightforward method for evaluating the thermal conditions of an office room and determining the optimal location of an air temperature sensor in PMV-controlled radiant systems was also proposed. This study contributes to the increasing field of research on thermal comfort and offers knowledge that is beneficial for the design and optimization of indoor environments.